Hydronic floor heating – vapor barrier or not?
Climate zone: 3b (Northeast BC, Canada)
I am installing a hydronic radiant floor heating system on top of a subfloor. There is an unconditioned crawlspace underneath the subfloor. Should I put down a poly vapour barrier or tar paper before I put down the radiant floor heating?
When I tore up the old floor back to the diagonal subfloor there was tar paper on top of it and then the first layer of flooring. I have since added 3/4″ T&G OSB as a new subfloor without any paper or poly between it and the diagonal subfloor.
The original flooring layers top down:
1″ diagonal fir subfloor
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